This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40AX50S, with the same bore, stroke, output force, port and mounting, so it fits the same application. The SAI replacement keeps the same ISO 15552 mounting interface, bore, stroke, output force and accessories, so it drops straight into existing fixtures. It is the current-production version of this cylinder with an upgraded piston seal.
Airtac SI40 Standard Cylinder SI40AX50S
The AirTAC Airtac SI40 Standard Cylinder SI40AX50S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 50mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40AX50S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke50 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40AX50S
- No minimum order. A single piece can be ordered.
- Ready in 3–5 business days. That is the time we take to process the order and hand it to the carrier. Transit time after that depends on the destination.
About the Airtac SI40 Standard Cylinder SI40AX50S
The AirTAC SI40AX50S is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 50mm stroke. It delivers 628N push force at 0.5MPa via a G1/4 port. AirTAC replaced this legacy unit with the SAI40AX50S, a direct upgrade sharing the exact ISO 15552 mounting interface, stroke, force, and accessories.
The SAI replacement features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and long life. The -A suffix denotes a SUS420J2 stainless steel rod, while the -S magnet works with legacy CS1-B/DS1-B sensors.
Airtac SI40 Standard Cylinder SI40AX50S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40AX50S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40AX50S |
| Bore size | Ø40 mm |
| Stroke | 50 mm |
| Acting type | Double acting |
| Port size | G1/4 |
| Rod thread | M12×1.25 |
| Fluid | Air (filtered by 40µm element) |
|---|---|
| Operating pressure | 0.15 – 1.0 MPa |
| Proof pressure | 1.5 MPa |
| Temperature | -20 to +70 °C |
| Speed range | 30 – 800 mm/s |
| Cushion | Adjustable, 27 mm |
| Max standard stroke | Up to 1200 mm |
Specifications follow the official AirTAC SI datasheet (now discontinued). The SAI40AX50S carries the same ISO 15552 ratings. Confirm against the product label before installation. Thread options: PT / G / NPT.
Theoretical Output Force (Ø40mm)
| Pressure | Push force | Pull force |
|---|---|---|
| 0.5 MPa | 628 N | 528 N |
| 0.7 MPa | 880 N | — |
| Max (@1.0 MPa) | 128 kgf | |
The SAI40AX50S produces the same force from the same bore. Actual usable force is lower than theoretical; size with a margin.
Model Code: Airtac SI40 Standard Cylinder SI40AX50S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×50 | Stroke length in mm. |
| -S | Optional built-in magnet for sensor position sensing. |
Legacy SI-family variants: SID (double rod), SIJ (adjustable stroke) — each maps to its SAI equivalent (SID→SAID, SIJ→SAIJ). Rod material: carbon steel (blank) / SUS420J2 (A) / SUS304 (B).
Where the Airtac SI40 Standard Cylinder SI40AX50S Is Used
Compact Clamping
Secures mid-weight machined parts in CNC fixtures using the 628N push force and 50mm short stroke.
Package Diversion
Actuates sorting gates and pushers on packaging lines where a 32kg safe vertical lift margin is sufficient.
Material Ejection
Ejects fabricated components from press beds, utilizing the SUS420J2 stainless rod for mild corrosion resistance.
Replacing the Airtac SI40 Standard Cylinder SI40AX50S with the SAI40AX50S
To replace the SI40AX50S, order the SAI40AX50S. Confirm the ISO 15552 mounting interface, 50mm stroke, G1/4 port, and your mounting accessory (LB, FA, TC, etc.). The -S magnet enables CS1-B/DS1-B switches, though the SAI uses current AirTAC sensors. Sizing down, a 32mm bore yields 402N push at 0.5MPa; sizing up, a 50mm bore yields 982N. A plain cylinder drifts on air loss, as cushions only decelerate—for load holding, use an external pilot check valve or the SAIL/BSAI lock variants. The SAIF variant adds a built-in valve if needed.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40AX50S
- ✓ Same bore / stroke / force
- ✓ Port/thread type (PT/G/NPT)
- ✓ Magnet (-S) for sensors?
- ✓ Mounting reused (FA/FB/CA/CB/CR/LB/TC)
Airtac SI40 Standard Cylinder SI40AX50S FAQ
Yes, the SI40AX50S is discontinued. The direct replacement is the SAI40AX50S. It shares the identical ISO 15552 mounting interface, 40mm bore, 50mm stroke, output force, G1/4 port, and mounting accessories, fitting directly into existing fixtures.
It features a G1/4 air port, a 16mm rod, and M12x1.25 thread. Force ratings are 628N push and 528N pull at 0.5MPa, 879N push at 0.7MPa, 1130N push at 0.9MPa, and a theoretical max of 128kgf at 1.0MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI40AX50S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40AX50S replacement — usually within 7-8 hours.